This invention relates to devices used for the lifting and lowering of one or more demountable cargo containers from transportation vehicles.
Devices which lift and lower demountable cargo containers are useful because of their ability to permit the same cargo containers to be carried by different vehicles. The cargo containers can also be removed from a vehicle to have their contents either unloaded or loaded without having to have the vehicle waiting. Likewise, a container can be filled and ready to be placed on a vehicle when it arrives without the vehicle having to wait to have the cargo loaded on the vehicle.
A device of this type was described in Fitch U.S. Pat. No. 2,069,236. This device utilized a vertical hydraulic cylinder connected to a horizontal plate to engage the underside of a cargo container for lifting and lowering the container. Marini U.S. Pat. Nos. 3,083,847 and 3,151,751 illustrate another device of this type utilizing a hydraulic cylinder connected to a sliding arm which engages the underside of a cargo container. Blackburn U.S. Pat. No. 3,764,028 illustrates another device of this type using mechanical linkage to turn a jackscrew to cause a horizontal plate to engage the underside of a cargo container. Miller U.S. Pat. No. 3,289,868 is another device of this type which uses a hydraulic cylinder with an attached horizontal plate to fit into a socket in the side of the cargo container to lift the container.